46 lines
1.4 KiB
C++

// Source : https://leetcode.com/problems/min-cost-climbing-stairs/
// Author : Hao Chen
// Date : 2019-02-04
/*****************************************************************************************************
*
*
* On a staircase, the i-th step has some non-negative cost cost[i] assigned (0 indexed).
*
* Once you pay the cost, you can either climb one or two steps. You need to find minimum cost to
* reach the top of the floor, and you can either start from the step with index 0, or the step with
* index 1.
*
* Example 1:
*
* Input: cost = [10, 15, 20]
* Output: 15
* Explanation: Cheapest is start on cost[1], pay that cost and go to the top.
*
* Example 2:
*
* Input: cost = [1, 100, 1, 1, 1, 100, 1, 1, 100, 1]
* Output: 6
* Explanation: Cheapest is start on cost[0], and only step on 1s, skipping cost[3].
*
* Note:
*
* cost will have a length in the range [2, 1000].
* Every cost[i] will be an integer in the range [0, 999].
*
******************************************************************************************************/
class Solution {
public:
int minCostClimbingStairs(vector<int>& cost) {
vector<int> dp(cost.size() , 0);
dp[0] = cost[0];
for (int i=1; i<cost.size(); i++) {
dp[i] = min( cost[i] + dp[i-1], cost[i] + dp[i-2] );
}
return min( dp[dp.size()-1], dp[dp.size()-2]);
}
};